io.delta.kernel.internal

Class TableFeatures

Object

io.delta.kernel.internal.TableFeatures

public class TableFeatures
extends Object

Contains utility methods related to the Delta table feature support in protocol.

Field Summary

Fields

Modifier and Type	Field and Description
static String	DOMAIN_METADATA_FEATURE_NAME The feature name for domain metadata.
static int	TABLE_FEATURES_MIN_WRITER_VERSION The minimum writer version required to support table features.

Constructor Summary

Constructors

Constructor and Description
TableFeatures()

Method Summary

Modifier and Type	Method and Description
static java.util.Set<String>	extractAutomaticallyEnabledWriterFeatures(Metadata metadata, Protocol protocol) Extract the writer features that should be enabled automatically based on the metadata which are not already enabled.
static boolean	isDomainMetadataSupported(Protocol protocol) Checks if the table protocol supports the "domainMetadata" writer feature.
static Tuple2<Integer,Integer>	minProtocolVersionFromAutomaticallyEnabledFeatures(java.util.Set<String> enabledFeatures) Given the automatically enabled features from Delta table metadata, returns the minimum required reader and writer version that satisfies all enabled table features in the metadata.
static void	validateReadSupportedTable(Protocol protocol, String tablePath, java.util.Optional<Metadata> metadata)
static void	validateWriteSupportedTable(Protocol protocol, Metadata metadata, StructType tableSchema, String tablePath) Utility method to validate whether the given table is supported for writing from Kernel.

Methods inherited from class Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DOMAIN_METADATA_FEATURE_NAME

public static final String DOMAIN_METADATA_FEATURE_NAME

The feature name for domain metadata.

See Also:

Constant Field Values

TABLE_FEATURES_MIN_WRITER_VERSION

public static final int TABLE_FEATURES_MIN_WRITER_VERSION

The minimum writer version required to support table features.

See Also:

Constant Field Values

Constructor Detail

TableFeatures

public TableFeatures()

Method Detail

validateReadSupportedTable

public static void validateReadSupportedTable(Protocol protocol,
                                              String tablePath,
                                              java.util.Optional<Metadata> metadata)

validateWriteSupportedTable

public static void validateWriteSupportedTable(Protocol protocol,
                                               Metadata metadata,
                                               StructType tableSchema,
                                               String tablePath)

Utility method to validate whether the given table is supported for writing from Kernel. Currently, the support is as follows:

• protocol writer version 1.
• protocol writer version 2 only with appendOnly feature enabled.
• protocol writer version 7 with appendOnly, inCommitTimestamp, columnMapping, typeWidening, domainMetadata feature enabled.

Parameters:

protocol - Table protocol

metadata - Table metadata

tableSchema - Table schema

minProtocolVersionFromAutomaticallyEnabledFeatures

public static Tuple2<Integer,Integer> minProtocolVersionFromAutomaticallyEnabledFeatures(java.util.Set<String> enabledFeatures)

Given the automatically enabled features from Delta table metadata, returns the minimum required reader and writer version that satisfies all enabled table features in the metadata.

Parameters:

enabledFeatures - the automatically enabled features from the Delta table metadata

Returns:

the minimum required reader and writer version that satisfies all enabled table

extractAutomaticallyEnabledWriterFeatures

public static java.util.Set<String> extractAutomaticallyEnabledWriterFeatures(Metadata metadata,
                                                                              Protocol protocol)

Extract the writer features that should be enabled automatically based on the metadata which are not already enabled. For example, the inCommitTimestamp feature should be enabled when the delta property name (delta.enableInCommitTimestamps) is set to true in the metadata if it is not already enabled.

Parameters:

metadata - the metadata of the table

protocol - the protocol of the table

Returns:

the writer features that should be enabled automatically

isDomainMetadataSupported

public static boolean isDomainMetadataSupported(Protocol protocol)

Checks if the table protocol supports the "domainMetadata" writer feature.

Parameters:

protocol - the protocol to check

Returns:

true if the "domainMetadata" feature is supported, false otherwise